docs: def _ncomponents(self):
          """
          :return: The `numerical_components` for an ODEModel. This differs from
              the traditional `numerical_components`, in that these component can
              also contain dependent variables, not just the independent ones.
  
              Each of these components does not correspond to e.g. `y(t) = ...`,
              but to `D(y, t) = ...`. The system spanned by these component
              therefore still needs to be integrated.
          """
          return [sympy_to_py(expr, self.independent_vars + self.dependent_vars + self.params)
                  for expr in self.values()]